SPECIALTY FERTILISER FOR MODERN AGRICULTURE
Mackay Potash ProjectThe Mackay Potash Project is forecast to be the world’s lowest cost producer of Sulphate of Potash (SOP). The project demonstrates outstanding Definitive Feasibility Study (DFS) economics with a post-tax real NPV8 of US$655 million and IRR of 21%, based upon a total cash cost of US$159 per tonne FOB and a flat SOP price of US$500 per tonne FOB (Wyndham Port).
The Mackay Potash Project comprises the four key elements of a bulk commodity project being the mine, processing plant, integrated logistics chain and port facility.
World Class Deposit
Mine
Sustainable Production
Processing
Integrated Efficiency
Logistics Chain
Worldwide Distribution
Port
Mine
Lake Mackay is the world’s largest undeveloped sulphate of potash (SOP) brine deposit and contains a drainable mineral resource of 123 million tonnes of SOP.
The project will extract SOP rich brine from shallow infiltration trenches across the lake surface. Brine will flow out of the trench walls and through the trench network assisted by the natural topography of the lake to the main feed canal at the south of the lake. The main feed canal will then transfer the brine with the assistance of six pumping stations into the evaporation pond system.
The evaporation pond system will comprise nine ponds covering an area of 30km2. Brine will be progressively transferred through this pond system to selectively crystalise specific salt minerals. The pond system has been designed to produce 3.0Mtpa of raw potash salts grading 14% K2O which will be mined by a fleet floating dredge style wet harvesters. The harvesters will utilise a cutting auger mounted to both the front and rear of the machine to cut precipitated raw potash salts from the pond floor and pump them as a slurry to the processing plant.
Processing
The processing plant has been designed to produce 450ktpa of SOP grading 52% K2O at steady state. The plant will receive 3.0Mtpa of slurried raw potash salts from the wet harvesters. Test work and process modelling shows an overall (pond & plant) potassium recovery of 80% for the process. Importantly the plant design has been specifically designed to operate in the hot, dry conditions of remote central Australia.
The slurried raw potash salts received by the plant will be sized to ensure adequate liberation of the k and then dewatered to minimise the amount of pond brine that moves forward into the plant. Pond brine is returned to its respective pond.
In a series of conversion crystallisation vessels the salt slurry will be converted into a single potash-bearing salt mineral called schoenite, by reacting with cooled SOP leach liquor from the back end of the process. The remaining slurry, will be predominantly schoenite and halite with traces of magnesium sulphate salts will be transferred to a flotation circuit.
The flotation circuit will separate the schoenite from most of the halite and the schoenite will be fed into leaching crystallisation vessels to remove any residual impurities prior to SOP crystallisation.
SOP crystallisation occurs at 50C with water to dissolve magnesium sulphate (MgSO4) and crystallise SOP (K2SO4). The resulting SOP slurry will be dewatered and dried. The SOP will then be stockpiled as standard SOP on site and hauled to the port.
Integrated Logistics
Lake Mackay is located 940km by road from its facility at the Port of Wyndham. In combination with Agrimin’s tailored logistics solution it should provide the project with one of the lowest transportation costs in the industry.
Agrimin proposes to construct a dedicated 346km sealed haul road to connect the Lake Mackay site with the public road network.
The Company has formed a joint venture called Newhaul Bulk with experienced WA bulk logistics operator Mr Craig Mitchell. The 50:50 incorporated joint venture will provide road haulage and road maintenance services for the Mackay Potash Project and crucially brings an important operational capability to Agrimin’s logistics chain.
A customised fleet of ~24 road trains will transport 450ktpa of SOP from Lake Mackay to Wyndham Port.
Lake Mackay is the world’s largest undeveloped sulphate of potash (SOP) brine deposit and contains a drainable mineral resource of 123 million tonnes of SOP.
Port
The proposed facility at Wyndham Port completes Agrimin’s fully integrated logistics chain. It will comprise of truck unloading, storage and barge loading facilities with a focus on minimising product rehandling and simplifying the shiploading process.
The port facility will be located on a 17 hectare waterfront property which is currently held by Agrimin under an Option Agreement to purchase.
The facility will provide Agrimin with a bulk shiploading solution that is specifically tailored for the Company’s SOP product. The barge load out facility will allow Agrimin to export its products in a range of cargo sizes upto Ultramax (62,000 DWT).
